Eric Reid on Track to Return

Eric Reid, recovering from the concussion he suffered in Seattle, will be tackling a familiar opponent in Trent Richardson.

The 49ers defense was on the practice field in Santa Clara when news arrived Wednesday afternoon of running back Trenton Richardson’s trade to its next opponent.

So the work started in earnest on Thursday.

“I don’t think we necessarily change the game plan,” rookie safety Eric Reid said. “We just know it takes a little bit more oomph to get him on the ground… He’s a hard runner. He likes to fall forward.”

Reid would know. San Francisco’s rookie safety played against Richardson collegiately, when they were at LSU and Alabama, respectively, in the ultra-physical SEC. They'll meet again at Candlestick Park, where Richardson's Indianapolis Colts come to visit on Sunday.

“The first time I played him, at Alabama, me and him went head up a couple of times,” Reid said, “I got him on the ground so he didn’t get anything after that.”

Reid’s last open-field tackle resulted in a concussion on Sunday in Seattle. He passed standard post-concussion tests on Wednesday and was wearing a blue, non-contact jersey during Thursday’s practice. He will have to pass one more test, on Friday or Saturday, to be eligible to play for the Week 3 matchup.

Reid said he didn’t have a headache last weekend, but he confirmed what Jim Harbaugh said postgame on Sunday. Reid didn’t immediately remember the play, when the team’s medical staff surrounded him at midfield, and that caused his diagnosis. The first-year pro did recall the play – he delivered a shoulder-first hit on Seahawks wideout Sidney Rice – once he was in the locker room.

The LSU product snared his second interception in as many NFL games that night and would no doubt like to make it a third. Tackling Richardson, if the Browns-turned-Colts ball carrier gets to the second level of the defense, will also be on his to-do list.

He’ll need all of his armor, to borrow a Harbaugh phrase, on Sunday. From all accounts, Richardson isn’t far off from Week 2 combatant Marshawn Lynch.

“He’s a very aggressive running back,” said defensive tackle Quinton Dial, who was Richardson’s teammate at Alabama and is now on San Francisco’s Reserve/Non-football Injury list. “We have to be ready to play and to hit him.”

Toward that end, defensive coordinator Vic Fangio had a tape prepared of Richardson’s 18 games in the NFL.

“It just gives them an upgrade at running back," Fangio said. "He’s strong. He’s fast. He’s got a good stiff arm. He’s a move-the-pile kind of guy, but he’s also got some shiftiness too where he can bounce it inside or outside.”

Richardson will play for his new team right away. Similarities between the running game styles in Cleveland and Indianapolis – Colts offensive coordinator Pep Hamilton is a protégé of Browns play-caller Norv Turner – give him a head-start.

“The playbook is about the same,” said Richardson himself in an interview with Colts.com. “It’s just about learning different terminology.”

Don’t assume that if Richardson is on the field, however, that he’ll be running the ball.

“A lot of the (pass) protections will be seamless for him,” said Fangio, who said he expects Reid and other ailing 49ers defenders not named Ian Williams to play on Sunday. “They’re may be some where they’re not comfortable with him yet, and they probably wouldn’t call those.

“It would not surprise me to see him play half the game or 90 percent of the game.”